This invention relates to display devices and particularly relates to a variable display device having a plurality of selectable display capabilities.
Display devices such as billboards, posters or shop signs have been widely constructed of a board having the advertisement or display material painted thereon. The board may or may not be provided with a frame and it may be erected on a free standing supporting structure or on a building. Such display device can show only a single message or display; and it is necessary to provide a plurality of such signs in order to show more than one display. A plurality of billboards and signs not only create an unsightly cluster of signs, but would also require a large area for their installation. Moreover, due to the duplication in cost and time in fabrication, they are expensive to produce and erect.
The drawback of painted billboards and signs have been mitigated by the use of a projection screen which is operative to show a plurality of displays, one at a time, on a single screen. Such projection signs are effective in drawing the attention of viewers after dark; however, they are difficult to view when the ambient is bright particularly during daytime. Accordingly, they are practical in displaying the information, at most, only half of a day and are thus not cost effective.